Testing machines are program-controlled to provide a series of output signals in various lines to energize a module to be tested. The module has outputs which are received by the machine and compared to what is expected from a properly operating module. A test fixture is supplied to connect to the input and output contacts on the test machine and organize their positioning for connecting to the input and output contacts on the module. This can be accomplished by wire-wrapping a breadboard, but such structure does not permit operation at high frequency. When hand-wired, each test fixture configuration requires a special noise and crosstalk suppression circuit just to get it operating, depending on how it was wire-wrapped. The higher the frequency of the test signal, the more complex becomes the tuning circuit. The tuning circuit often consisted of extra filter capacitors and special termination circuitry which in itself affected the test being done. In some cases, rerouting of a wire was necessary in order to avoid undesired coupling. Thus, prior test fixtures each had their own individual character so that repeatability between test fixtures was difficult to achieve.